Earpiece with inflatable sealing means



Dec. 26, 1950 R. B. BLAND 2,535,258

EARPIECE WITH INFLATABLE SEALING MEANS Filed Dec. 5, 1947 IN VEN TOR.

w g ww Patented Dec. 26, 1 950 EARPIECE WITH INFLATABLE SEALING ANSReginald B, Bland, Newport News, Va.

Application December 5, 1947, Serial No. 790,002

Claims.

This invention relates to ear pieces for audiphone receivers and moreparticularly to the ear tip or portion of the ear piece adapted to enterthe auditory canal of the ear.

In modern audiphone practice an amplifier of either the microphone orvacuum tube type is ordinarily used between the transmitter and receiverand since the gain used at times may be as much as 50 decibels or more,special precautions must be taken to avoid singing due to acoustic orother coupling between the output and input circuits. This is true eventhough the pickup transmitter is mounted on some part of the bodyrelatively remote from the receiver. The problem of singing becomes evenmore acute when an attempt is made to mount the pickup transmitter andthe receiver in a single casing as where the transmitter and receiverare integrated into a single unit to be carried at the ear of the user.Even though an integrated transmitter and receiver combination wasuggestedras far back as 1912 as shown in the patent to Soret No.1,154,069 and though many advantages result from having the pickuptransmitter and receiver mounted in a single casing near the ear of theuser, the use of such integrated transmitter, receiver audiphone units,particularly where the acoustic gain desired is high, has been largelyprevented due to this acoustic coupling between the pickup transmitterand the receiver commonly referred to as feedback.

Acoustic feedback, which is characterized by the presence of acontinuous whistling sound of more or less fixed pitch, results as aconsequence of the introduction of exciting forces on the diaphragm orpressure sensitive element of the transmitter which are translated intofluctuating electric currents, amplified, caused to vibrate thediaphragm of the receiver, and are thereby converted back, in whole orin part, into exciting forces on the transmitter diaphragm. An unstablecondition then exists and the exciting forces build up until theamplifier is overloaded and further increase becomes impossible.

One of the primary sources whereby vibrations of the receiver diaphragmare converted back into exciting forces picked up by the transmitter isthrough an air path due to leakage between the ear piece of the receiverand the auditory canal. Ear pieces as commonly used are made of rigidand inflexible material while the size and shape of the ear canalchanges from day to day and hour to hour with the individualperson. Thusthe ear piece may be uncomfortably tight in the morning and loose atnight. Pulling on the lobe of the ear, or pressing on the skin of theadjacent check, as by lying on a pillow; or resting the head on thehands will change the shape of the canal from approximately circular tooval, thus permitting the sound waves inside the canal to gain egress tothe outside air and hence to the transmitter. In fitting hearing aids itis well known that the higher "the acoustic gain required to bring thesound intensity up to a level that will be audible to a person hard ofhearing the tighter the fit must be between the ear piece and theauditory canal. Where a person is particularly hard of hearing oftennothing can be done for him since it is impossible, with known earpieces, to obtain the necessary seal between the ear piece and the earcanal for the high acoustic gains required so that for such peoplewearing a hearin aid results only in a continual and high pitchedwhistling sound.

It is therefore the primary object of my invention to provide an earpiece for audiphone receivers in which the ear tip, or portion of theear piece adapted to enter the auditory canal of the ear, once fitted tothe ear of the user will automatically adjust itself to changes in thesize and shape of the ear canal so as to provide a satisfactory sealbetween the ear tip and canal at all times when in use.

It is a further object to provide an ear tip which can be adjusted tofit ear canals of various sizes and in varying degrees of tightness sothat the pressure exerted by the ear tip on the sides of the canal canbe carefully adjusted by the one fitting the hearing aid so as toprovide a satisfactory seal and, at the same time, a seal that will notbe uncomfortably tight,

Other objects and advantages of the invention will be apparent on studyof the following description of a preferred embodiment of the inventionin conjunction with the appended drawings in which,

Figure 1 is a perspective view of an audiphone receiver and attached earpiece, the ear piece being formed in accordance with the presentinvention;

Figure 2 is a side view of a portion of the ear piece showing the eartip in cross section; and

Figure 3 is an enlarged detail sectional view of the inflatable hollowtorus carried by the ear tip.

Referring to the drawings, numeral 1 indicates generally the receiverunit or an integrated transmitter receiver unit of an audiphone which}has attached thereto an ear piece 2 having a portion 3 molded to fit theconcha of the ear and an ear tip 4 adapted to enter the auditory canalof the ear. The molded portion 3 and the ear tip 4 serve to hold thereceiver and. ear piece securely in place in the users ear. The ear tip4 is provided with an air passage 5 therethrough which is incommunication with the receiver 1 and serves to transmit soundvibrations from the receiver l into the auditory canal of the ear.

In order to obtain a tight seal between the ear canal and the ear tip 4to prevent air leakage therebetween which might result in feedback ofthe sound pulses to the pickup transmitter, an inflated flexible, hollowtorus 6 is provided which is fitted securely to the ear tip. As shown inthe drawings the torus 6 comprises a flat base section 1 and an arcuatetop section 8. The respective edges of the section 1 and 8 are securedto each other by the use of a suitable adhesive or other means toprevent any leakage of fluid therebetween. In the preferred modificationboth the base section '5 and the arcuate top section 8 are made ofrubber, the arcuate top section 8 being formed of a self-sealing rubbermaterial through which a hollow needle 9, such as that of a smallhypodermic needle, may be inserted to force air or some liquid such asalcohol between the sections 1 and 8 to inflate the torus to the desiredsize. in a groove It formed around the outer periphery of the ear tip 4the groove lil being of such depth that the edges of the torus 6 aresubstantially flush with the outer periphery of the ear tip 4.

Care should be taken when fitting the torus 6 to a the ear tip 4 thatthere is no leakage path between the torus and the ear tip. This can beprevented by providing a tight fit between the torus and the ear tip orby the use of some sealing material such as a rubber or other cement.

When fitting the ear piece to the customer, the fitter inserts theneedle 9 of a syringe or like instrument ll through the self-sealingmaterial of the inflatable torus 6 and injects air or a liquid such asalcohol into the interior of the torus until the torus is inflatedenough to provide a sufficiently tight seal to prevent feedback at theamplification necessary in the particular instance and yet at the sametime not to have the seal so tight as to cause uncomfortable pressure onthe sensitive inner walls of the ear canal of the user.

It is obvious that if the ear tip is formed to fit too tightly afterbeing inflated a portion of the inflating fluid can be removed in thesame manner in which it is injected into the inflatable torus, thusenabling the fitter to provide a considerably more satisfactory fit thancan be obtained with present known ear pieces. Due to the adjustabilityof ear pieces embodying the present invention, the necessity of carryinga large variety of sizes in stock will, to a considerable extent, beeliminated since the Year tip, which is the critical part of the earpiece, can easily be adjusted to fit varying sizes of auditory canals.

Once the ear tip has been adjusted by the fitter to the customer theinflated torus provides a yielding cushion seal that will adapt itselfto all changes in shape of the ear canal and thus provide a good sealdespite such changes. It is apparent that the inflation or deflation ofthe torus is not necessarily limited to the fitter from whom the earpiece is purchased but may be controlled by the wearer after he hasbecome familiar with the adjustment best suited to his needs. Thenecessity therefore of periodically returning The torus 6 in theembodiment shown lies I 4 to a dealer in audiphone equipment to obtain anew car piece every time there is a slight change in size of theauditory canal is eliminated.

It is apparent that hollow inflatable tori or annulate elements ofvarious types and forms may be used, for example the base member 1 ofthe embodiment shown, need not be of rubber nor even of a flexiblematerial so long as a tight seal is maintained between the base I andthe outer surface of the ear tip to prevent any air leakagetherebetween. Furthermore, the top arcuate section 8 need notnecessarily be formed of rubber but may be made 01"- any elasticmaterial provided the material is sufficiently impervious to prevent anyleakage of the inflating fluid therethrough; it would also not benecessary to form the whole of arcuate section 8 of a material havingself-sealing properties but only a small portion thereof may be formed,if desired, of selfsealing material to receive the needle 9. The arcuateportion 8 may even be attached at its edges to the ear tip 4 by means ofa suitable rubber or other cement, thus eliminating th base 1' yetpermitting inflation in the manner hereinbefore described.

It is further apparent that the inflatable torus may take a number ofdiiierent forms in cross section, such as circular, elliptical,rectangular, etc. and may extend over a lesser or agreater portion ofthe ear tip as desired. Other valve means than the use of a self-sealingmaterial also be provided for the insertion of the inflating fluid intothe hollow torus, such, for example, as providing a fluid conduitpassing through the ear piece and having one end'of the conduitterminating in communication with the interior of the torus t and theother end of the fluid conduit emerging at some point on the surface ofthe ear piece as separate from the ear tip and being provided with aconventional valve.

It is apparent from the foregoing that there may be numerousmodifications and embodiments of the invention beside that which hasbeen described and illustrated. The invention is therefore not to belimited to the particular embodiment shown as one method of carrying outthe invention but should be only limited by that which is claimed.

Having thus described the invention, what is claimed and desired to besecured by Letters Patent is:

i. ear piece having an ear tip adapted to enter the auditory canal ofthe ear, and inflatable hollow flexible sealing means fixedsurroundingly on said ear tip to prevent leakage of air between ear tipand said auditory canal.

2. In combination receiver, an ear piece secured to said receiver, saidear piece being provided with an ear tip having an air passagetherethrough communicating with said receiver, said ear tip beingadapted to enter the auditory canal of the ear and bearing hollowresilient sealing means thereon, said resilient sealing means beinginflatably adjustable in diameter so as to closely fit auditory canalsof varying internal diameters.

3. An ear piece for an audiphone receiver comprising a portion adaptedto fit in the concha of an ear, an ear tip adapted to enter the auditorycanal of the ear, and an inflatable hollow torus secured to the outerportion of said ear tip. the outer diameter of said hollow torus beingadjustable by inflation so as to closely contact the inner walls of theauditory canal regardless of changes in diameter or contour of saidauditory canal.

4. An ear piece having an ear tip adapted to enter the auditory canal ofthe ear, said ear tip having a hollow, flexible torus secured to itsouter surface to prevent leakage of air between said ear tip and theinner surface of said auditory canal.

5. An ear piece for audiphone receivers having an ear tip adapted toenter the auditory canal of the ear, said ear tip having an inflatabletorus around the outer periphery thereof adapted to provide a flexibleseal between the outer surface of said ear tip and the inner surface ofthe auditory canal.

6. An ear piece for audiphone receivers having an ear tip adapted toenter the auditory canal of the ear, a hollow inflatable torus securedto the outer periphery of said ear tip to provide a flexible sealbetween the outer surface of said ear tip and the inner surface of theauditory .canal. said torus being of substantially greater ffwidth thandepth.

.7. An ear piece as in claim 5 in which the inifl'atable torus comprisesa flat annulate base member, and a top annulate member having its edgessecured to the edges of said annulate base 5 member to provide a spacetherebetween adapted to receive an inflating fluid.

1 3. An ear piece for audiphone receivers having a flat annulate basemember and a top annulate member. former of an elastic self-sealingmaterial having its edges secured to the edges of said annulate basemember to provide a space therebetween adapted to receive an inflatingfluid.

9. An ear piece for audiphone receivers comprising a portion molded tofit the concha of the ear, an ear tip adapted to enter the auditorycanal of the ear, an air passage extending through said. ear tip andsaid ear piece adapted to communicate with said receiver, a grooveextending around the periphery of said ear tip, and an inflatable hollowflexible torus secured in said groove.

10. An ear piece for audiphone receivers comprising a portion adapted tofit the concha of the ear, an ear tip adapted to enter the auditorycanal of the ear, and a flexible annulate member encircling said tip,the edges of said flexible annulate member being secured to the surfaceof said tip in such manner that the flexible annulate member defines,with the surface of the tip, a fluid-tight chamber.

REGINALD B. BLAND.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 2,246,737 Knudsen June 24, 19412,430,229 Kelsey Nov. 4, 1947

